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The LOOK 596 frameset and Zed crankset

Last time I hinted at some of the technical features of the LOOK 596 time trial frame. Many of them were introduced on other bikes. The clever E-post integrated seatpost design has been adapted to the deep section seat mast of the 596. Since the R32 version of the E-post is reversible, the rider can configure the saddle position far forward to suite triathletes or slammed back for Pro Tour riders.

The Monobloc fork has been a distinctive feature of LOOK’s time trial bikes for years, but the 596’s fork refines the idea somewhat. While retaining the narrow 20mm needle bearings of the previous generations, the 596 fork adds an 1-1/8 bearing at the bottom. Keep in mind that the Monobloc fork gets much of its stiffness from the fairing portion in front of the head tube, as the fork legs blend into the fairing rather than neck down to pass through a small headset bearing. Available in four lengths, the proprietary stem articulates from a 2-position mount in the fairing and has a 31.8mm handlebar clamp.

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The really trick part of the 596 is undoubtedly the Monobloc Zed crankset. It is a one-piece, hollow carbon crank. Read that again: one-piece. Instead of dealing with the issues of keeping that lefthand crankarm attached to the spindle (which must be surprisingly difficult for carbon crank manufacturers, based on what I see as a mechanic), LOOK sidesteps the problem by integrating both arms into a monster spindle. The only metal components to the 320gr crank are the machined bearing seats on the spindle. The 596 goes beyond the oversized BB30 frame standard in terms of size. To install the Zed, the left crankarm is snaked through the BB shell and then a lockring is tightened to hold the crank and cartridge bearings in position. The whole system should seem familiar to any mechanic who has worked on an American-style BMX bottom bracket or an Astabula crank.

The carbon spider is essentially a plate of carbon fibre drilled for both 110mm and 130mm bcd chainrings, providing options for both standard and compact double chainring set-ups. If anything, this feature points to LOOK’s intention to bring this crank to their road frames, as a compact double has little use on an elite time trial bike. By LOOK’s claims, the Zed just misses beating the very lightest cranks on the market on weight but blows them all away on stiffness.

A unique feature of the Zed crank is the pedal interface called Trilobe Technology. Rather than having aluminium threads anchored into the carbon structure, the Zed has a rounded and tapered socket moulded into the carbon. A special Zed version of LOOK’s Keo pedal has the matching titanium plug, from which the pedal spindle is eccentrically machined. By rotating the plug in the crank socket, one designates the effective crank length from 170 to 172.5 to 175mm. A fixing bolt then holds the pedal in place. It appears as if only the Keo Zed pedal will be compatible with the Zed crank.; otherwise, the 596 comes with a BB adapter for traditional, English-threaded BB/cranksets.

With choice of one stem, the whole kit of frame/fork/headset/crank/pedal/seatpost should retail for $4,999. Frankly, that is a bargain when talking about the big leagues of bicycle bad-ass. When posh, a la carte components like Zipp cranks cost $1000 and aero forks start at $500, the LOOK 596 stacks up really nicely against the competition. The display bike weighed 16.5 pounds with SRAM Red and rear disc.

A track version will be available for $11,000 (um forget about what I said about bargains).

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5 Comments

I don’t want to fault LOOK for taking a new approach, but the “X grams lighter but Y% stiffer” claim must be the “laterally stiff and vertically compliant” of cranksets. If the benchmarketing is to be believed, first generation carbon cranks (FGCC) had the rigidity of clay, and the new models firebrick.

For a moment I’ll accept that power men like Cavendish or Bos can count the watts they save with alloy cranks compared to modern carbon blindfolded, but we’re talking *peak* power there. Sounds awesome on the track, but Thor Hushovd’s prologue bike (which happens to be a 596) is the only sensible application on pavement.

That’s one sexy crank. What always confused me about Carbon Cranks was how ugly they were: FSA being the most ugly. Also, I can move a SRAM carbon crank arm with my hand by grabbing the chainstay and pushing the crank arm with my thumb. Try that with forged DA, don’t move. What does that prove? Don’t know exactly, but it’s worth noting.

another interesting idea is how stiffness is measured, ie in what direction. I often do the same flex test that Byron is doing, which is a very coarse comparison. But that only measures flex in one direction. Arguably resistance to twist is more important, but not a whole lot of companies explain how they get the numbers.

Also, the Zed crank isn’t going to work on the track. Wrong bcd for track rings. Besides, most world-class track riders use SRM cranks, and the company literature depict the 596 track with a standard BB.

True, they’re going to want 144s there. I was just trying to keep it positive and find a good application. I should add that variable crank length is a nifty idea.

We all hear the same marketing releases. That carbon crank from Shimano is allegedly the most feather-light and granite hard component they’ve ever made, but it only seems to exist on paper. My only experience with carbon cranks is second hand from people who come away complaining less about stiffness than price.

One of the issues with carbon cranks is the finish. It’ll scratch, nick, mar, and get beat up very quickly. Specialized is the worst. You can sneeze in the direction of that crank and it scratches. Whatever clearcoat the manufacturers are using, they need to improve it. One chain drop off the chain ring and onto the crank and there’s a gash.